Pathology Lecture 2 Flashcards
Equine Upper airway: Strangles
What does strangles start as and become?
Starts as rhinitis and lymphadenitis–> spreads
to sinuses, guttural pouches
Equine Upper airway: Strangles
What is the systemic form of strangles?
Systemic abscessation = “Bastard Strangles”
Purpura hemorrhagica = type 3 hypersensitivity (swidespread hemorrhage, edema, etc)
Equine Upper airway: Strangles
Horses that recover may become:
carriers
If you have a case of strangles what should you do with your horses to manage the disease from spreading?
quarantine
Strangles can create what in the guttural pouches?
chondroids – solid ball of pus
Glanders will cause what type of disease?
2 forms
Leads to pyogranulomatous inflammation progressing to ulceration
The cutaneous form = “Farcy”
What other bacterial infection in horses looks like Glanders?
Pseudoglanders (melioidosis)
Pseudoglanders (melioidosis) and Glanders have the potential to spread where>
Lungs and beyond
What spp. are susceptible to Pseudoglanders (melioidosis)?
Horses, people, cattle, pigs, goats, sheep, and cats
What is the fungus that causes Guttural pouch mycosis?
Aspergillus spp.
Its oxygen loving
Whats the sequella of guttural pouch mycosis?
Fatal hemorrhage
Parasitic upper airway in equine
o Rhinosporidium seberi
Neoplastic upper airway in equines
Squamous cell carcinoma
What is the pathology of Infectious bovine rhinotracheitis: Bovine herpes-1?
Fibrin, hemorrhage, necrosis
(ulcers), diphtheritic membranes
Nasal –> bronchial
Red nose
What does BHV-1 have on histo?
intranuclear
inclusion bodies
improper dehorning in bovines leads to
Frontal sinusitis
Tooth infections in bovines can lead to
Maxillary sinusitis
Oestrus ovis causes pathology and respiratory issue because??
the larvae of a fly that get deposited waaaaaayyyyyy back in the sheep nasal passages
Leads to local irritation (as one would imagine) and possible secondary bacterial infections
What causes Enzootic nasal tumors?
Caused by a retrovirus infection
Enzootic nasal tumor virus – 1 (sheep) or -2 (goats)
Enzootic nasal tumors have an affinity to what area in head?
ethmoid areas
Whats the sequela of atrophic rhinitis?
Deviation of nasal septum, Secondary infections (because of loss of defense mechanism of nasal turbinates), poor doers
Whats the pathogenesis of atrophic rhinitis?
- Infection with Bordatella bronchiseptica –> produces dermonecrotoxin
- Promotes infection with toxin producing strains
of Pasteurella multocida –> - P. multocida toxin promotes osteoclast
proliferation AND inhibits osteoblast activity –> - Resorption of nasal turbinates
What are the clinical signs of a dog with rhinitis?
sneezing, discharge,
epistaxis, masses
What of inflammation is associated with canine viral rhinitis?
lymphoplasmacytic inflammation
Bacterial canine rhinitis is characterized by what type of inflammation?
suppurative
Fungal infections in the canine nasal area lead to:
granulomatous rhinitis
Idiopathic canine rhinitis is most likely what type of inflammation?
Lymphoplasmacytic
Allergic canine rhinitis has most likely what type of cell present?
eosinophils
Grossly what does neoplasia in canines look like?
Grossly, it may mimic granulomatous inflammation
Feline Viral Rhinotracheitis: Feline Herpes virus causes what that can lead increased risk of secondary infections?
Leads to impaired host defenses increasing the risk for secondary infections
What are some common secondary bacterial infections in a cat with Feline herpes virus?
Mycoplasma, Bordatella bronchiseptica, Streptococcus spp
Secondary infections results in what clinical signs in a cat with Feline herpesvirus?
Secondary infections –> suppurative or catarrhal rhinitis and
conjunctivitis
* Ocular discharge and keratitis common
What is the clinical manifestation of FCV?
Also oral ulcerations
Severe lower airway disease
Has a form characterized by systemic fever and hemorrhage = up to 50% fatalities
What does Feline Chlamydia cause in terms of pathology?
Leads to conjunctivitis and serous to mucopurulent rhinitis
What is a significant clinical sign of Cryptococcus rhinitis?
Causes space occupying masses commonly filling the nasal cavity (and sometimes extending into the brain) –> Roman nose
Whats the most common lymphoma in cat nasal area?
B cell by far most common
Lymphoma vs Squamous cell carcinoma in felines grossly?
Lymphoma- soft and white
SCC- firm and tan
Nasopharyngeal (or aural) polyps are likely to be secondary to what?
Chronic inflammation esp with otitis
Who is most susceptible to Nasopharyngeal (or aural) polyps in cats?
young cats most frequently
What is the likely clinical result of - Viral hemorrhagic disease in rabbits?
Terminal fatal epistaxis or sudden death
Snuffles results in what pathology?
Results in severe mucopurulent rhinosinusitis
where is white nose in bats
limited to the skin of the nasal planum
Fowl Cholera is characterized by what inflammation and clinical signs?
Characterized by heterophilic to granulomatous inflammation
See severe facial swelling
May also cause a fibrinosuppurative polyserositis
Who is likley to get Mycoplasma gallisepticum?
Backyard flocks
Its highly contagious
Mycoplasma gallisepticum causes what type of sinusitis?
Causes chronic heterophilic to granulomatous sinusitis, conjunctivitis
What is the pathophysiology of tracheal collapse?
tracheal cartilage dysplasia –> development of abnormal cartilage rings and a widened dorsal tracheal membrane
Grossly what do you typically see in tracheal collapse?
dorsoventral flattening of the tracheal rings with widening of the dorsal tracheal membrane.
What is tracheal dysplasia?
Development of abnormal tracheal cartilage rings +/- redundant tracheal membranes
May or may not be clinically significant
Could predispose to choke if severe enough due to compression of the esophagus
What is tracheal hypoplasia?
Tracheal lumen smaller than normal
Sometimes associated with bronchial hypoplasia
What nerve is damaged in laryngeal paralysis?
Left recurrent laryngeal nerve
Damage to the left recurrent laryngeal nerve Atrophy and fibrosis of left dorsal and lateral crycoarytenoid muscle
What kind of atrophy is in “Lar Par”?
denervation atrophy
What are the clinical signs of lar par?
Inspiratory noise, exercise intolerance
Lar par can occur secondary to:
Can also occur secondary to infections of guttural pouches/lymph nodes, trauma, etc. that result in damage to the nerves
What is the cause of laryngeal edema?
Leaky vessels due to:
- Anaphylactic shock
- Inflammation (pigs with edema disease, horses with purpura hemorrhagica)
- Allergies
- Trauma: i.e. Intubation
Narrows the lumen
What can laryngeal and tracheal hemorrhage be caused by ?
Can be agonal (associated with dying, see above)
Can be iatrogenic
Can be REALLY bad: African swine fever, hog cholera, equine infectious anemia
Is tracheal foam a normal PM finding?
- A little is normal
- Think pulmonary edema if excessive
What is the cause of Follicular lymphoid hyperplasia? When can you typically see it?
Common, usually incidental, and non-specific
Common in young racehorses
- Ddx from mucous glands
If severe, can lead to partial obstruction
May see this during intubation/endoscopy
What is follicular hyperplasia?
lymphoid tissue that becomes hyperplastic when responding to antigenic stimulation leading to nodules
Smoke inhalation leads to what?
tracheal inflammation (and pulmonary inflammation). Lumen will often be stained black from the carbon
Where does tracheal obstruction occur?
Can happen anywhere along the trachea
Epiglottic entrapment in horses is caused when?
Epiglottis gets entrapped by arytenoepiglottic fold
Horses may cough violently or seem to be choking as they attempt to correct this entrapment
Dorsal displacement of the soft palate leads to:
Leads to increased resistance, turbulence
Often a dynamic process (may not get stuck that way permanently)
What are the clinical sign associated with Dorsal displacement of? the soft palate
Decreased performance and exercise intolerance
Where does the fungus like to grow in guttural pouch mycosis? Whats the sequela of this diease?
Fungus (usually Aspergillus) grows around internal carotid artery (leads to granulomatous inflammation)
Sequela?
- Hemorrhage
- Nerve damage –> dysphagia, Horner’s syndrome
What is guttural pouch tympany and who is mostly likely to get it?
Entrapment of air within the guttural pouch
Most common in foals
With guttural pouch tympany what would you see at necropsy? What would you rule out based on this?
- No real changes at necropsy other than dilation
- Rule out from Strangles based on external appearance
Necrotic laryngitis leads to what pathology grossly?
Leads to fibrin, necrosis, ulceration
What would predispose a cow to necrotic laryngitis?
Viruses and trauma predispose (also contact ulcers, as below) –> local area of ulceration is a great environment for Fusobacterium to gro
Contact ulcers are most common in what bovines? This predisposes them to what?
Feedlot cattle
- Excessive mooing?
Predisposes them to necrotic laryngitis
What are the 4 pathologic components of brachycephalic airway syndrome?
Stenotic nares
Elongated soft palate
Hypoplastic trachea
Everted laryngeal saccules
How do everted laryngeal saccules contribute to BAS?
The two little sacs on either side of the larynx (beneath the vocal folds) bulge out (usually with edema) and into the lumen –> impedes airflow
What is brachycephalic airway syndrome worsened by?
All of these things are worsened by secondary edema when animals are in respiratory distress
Where does oslerus osleri in dogs go to in the respiratory tract? and what does it cause?
Causes submucosal nodules (filled with awesome nematode parasites!) throughout the trachea and bronchi
- Grossly, see tan to brown to red nodules along the tracheal and bronchial mucosa (plus worms if you are lucky!)
Not accompanied by much inflammation
See this worldwide in both domestic and wild canids
What does bronchiectasis occur secondary to? and what happens to the bronchi because of it?
- Occurs secondary to chronic obstruction and inflammation
- Damage to bronchiolar walls and PERMANENT dilation of bronchi
Bronchiectasis is common in what animals with what infection? Why?
Common in cattle, rats with Mycoplasma infections
Remember where Mycoplasma likes to live (between the
cilia) and this likes to adhere to bronchi
Describe how bronchiolitis obliterans?
This change occurs secondary to necrosis of the bronchioles that gets repaired by fibrosis. Eventually the epithelium grows back along the surface, but by this point the lumen is V. NARROW because of this polypoid projection, and the breathing is not so good
Bronchiolitis obliterans is…
PERMANENT
Feline asthma leads to:
hypertrophy of the bronchial wall (smooth muscle)
What are the characteristic of hypertrophy of the bronchial wall in feline asthma?
characteristic “donut” lesions on radiographs
bronchoconstriction
What is the other form of hypertrophy in feline asthma?
Glandular hypertrophy which contributes to excessive mucous
Mucus becomes thicker and more abundant –> makes it still harder to clear the airways
What inflammatory cell might you seein feline asthma?
eosinophils
you might see lymphocytes or plasma cells if chronic
Feline asthma predisposes you to
secondary infections
What are the clinical signs of feline asthma?
Clinically, this condition results in bronchospasm episodic bronchoconstriction (cats may wheeze or cough)
What environments make dogs more susceptible to Canine infectious respiratory disease complex?
Kennels, shelters, veterinary clinics increase
risk
Canine infectious respiratory disease is said to be multifactorial. What other infectious agents are these dogs suscpetible to?
Bordatella bronchiseptica, Strep. zooepidemicus, Mycoplasma cynos
Canine parainfluenza-2, Canine coronavirus, Canine influenza most common
Poor ventilation predisposes
What do canine infectious respiratory disease complexes look like grossly?
Catarrhal to mucopurulent tracheobronchitis
–> suppurative with Bordatella infection
What are the clinical signs associated with canine chronic bronchitis?
Chronic coughing
Vascular changes → pulmonary hypertension
- May → heart failure (cor pulmonae)
What cells do you see on histo in canine chronic bronchitis?
Goblet cell hyperplasia, epithelial hyperplasia
Vascular changes = increased smooth muscle in arteries
Bovine mycoplasma pneumonia is known as (morph dx)
Severe chronic regionally extensive suppurative bronchiopneumonia (with bronchiectasis)
What does chronic bovine mycoplasma pneumonia result in?
Bronchiolitis obliterans:
Remodeling of the airway by fibrosis → terrible gas exchange
Where else other than the lungs does bovine mycoplasma affect?
May also see suppurative otitis media. Over time, the middle ears can get so full of pus that they can have remodeling of the bones there! Clinically, calves may display a head tilt. If you see suppurative otitis media in a calf, your first 4 thoughts should be Mycoplasma bovis infection
Possible morph
Bilateral, diffuse, severe, chronic (or chronicactive) suppurative otitis media
What can you also see with pulmonary hypoplasia?
May see with congenital anasarca or congenital diaphragmatic hernia
Lung lobe torsion may lead to:
May lead to infarction
- Infarction is otherwise RARE in lungs because of redundant blood
supply
What is the cause of hemosiderosis (brown lungs)?
Hemosiderin-laden macrophages indicate chronic ingestion of red blood cells
Usually secondary to congestion in the lungs because red blood cells eventually leak out of dilated vessels and into the alveolar lumens
What disease might lead to hemosiderosis?
Heartworm disease in dogs (Dirofilaria immitis) infection leads to
chronic passive congestion.
Chronic heart failure in dogs, for the same reason (chronic congestion)
alveolar macrophages that break down red blood cells and edema
What are “heart failure cells”?
hemosiderophages
**
Whats the significance of anthrocosis?
nothing, its just a result of being an animal on earth
What can silica be associated with?
can be associated with osteoporosis in horses
Osteoporosis: bones become brittle, enlarged due to loss of normal
bone
Melanosis in the lungs can occur in what species?
Pigs, guinea pigs, and some others